Sourdough Hydration Calculator

I made a simple Hydration Calculator.  I've tried to use a few other online hydration calculators and there are so many textboxes that I don't know what to do with them all!  This one has NO text fields.  Instead, each colored box represents one or more variables: flour, water, starter.  Just drag the box bigger or smaller to change the quantity and everything is calculated on the fly.  I love to make sourdough and I'm always playing with my recipes, or finding myself with too little or much of one ingredient or another.  I think this calculator makes it easy to play with a recipe and tailor it to your own needs.  I'm no professional baker so it might not seem suitable for the pros, but I've checked it against a handful of my favorite recipes and found it gives accurate results.  It is open source as well so if you are inclined to dabble in that sort of thing you can click the 'fork me on github' banner to get your own copy of the source code (Maedi I'm talking to you) ;).


not sure why i see my screenshot twice... can't figure out how to fix that.  sorry. 

Fixed the double image for you Josh, no worries. Great calculator.

I've got a GitHub account so expect a fork in the future ;) How's California? Are you in the valley tech scene?

 Hey maedi, thanks for fixing the image.  Loving California.  Not saying it's better than Victoria, but it is a helluva lot closer to our families :)  Not in the valley; I work in San Francisco, but it is close enough that at night you can hear all the startups and venture capitalists doing their weird dance. ;)



Hi Joshua,

Nice work.

Would be good to be able to set a hydration > 99% for the starter. Perhaps this is a browser thing. I've tried it in safari and FF on OSX but I can't drag the starter hydration past 99%.



 How high should hydration go?


I've never seen anyone call for anything over 100%  in a recipe, but I'm sort of a noob.  What are the benefits of > 100% hydration starters?  Anyway, other people have complained about this as well so I'll probably use a 2x multiplier so that hydration goes up to 200% but still is constrained by the starter mass box.


If you have suggestions about a better interface for the starter I'm all ears.  That was simply the best I could come up with, and it seemed pretty natural to have the hydration fill up the starter mass box.



I use a rye starter and rye needs more water than wheat. I used to use 125% hydration for the rye but switched to 200% after reading Andrew Whitley's Bread Matters.


I see what you mean about it being natural to have the hydration fill up the starter box on the assumption that you only ever have 100% hydration. If you're going to have > 100% then you'll probably need to split the starter section into separate flour and water bars.




 The starter hydration now goes up to 200%.  I haven't decided what to do about any of the other bug or feature requests I have gotten.  This was the only one with a clear problem/solution so I fixed it first.  Thanks for the feedback.  Keep it coming.

Hello Joshua,

Is it meant that if you change the starter mass the starter hydration changes as well.  For example if starter was say 180g at 99% and you change the hydration to 50% then change the mass to 145g, the hydration has changed to 38%.

Or figures somehing like that any way.



Hey Farinam,

The starter hydration / starter mass relationship is not defined by the calculator.  Currently the hydration moves the same number of pixels as the mass.  This was a simple (read: lazy) solution and unfortunately doesn't maintain the ratio.  I agree that it should maintain the ratio as you drag it, and I'll fix it some weekend soon.  Thanks so much for the feedback!



I think I got this bug captured here

Hello again Joshua, I was wondering what the Lock Hydration function is for. I'd have thought it was to let you calculate ingredients for varying mass of dough but it seems to freeze the starter mass as well so that the starter ratio varies - or am I misunderstanding something? Regards Farinam

[quote=farinam]...I'd have thought it was to let you calculate ingredients for varying mass of dough but it seems to freeze the starter mass as well so that the starter ratio varies...[/quote]


I saw this too. Suppose I should do as Maedi and fork it and fix it instead of whinging about the bugs. I've been wrestling with git for a few weeks now on another project and it's doing my head in. Damn CVS/SVN has a completely different mindset and learning the git way is proving tricky.



 github has really good and easy to follow instructions for most basic operations.  If you need a good resource for a deeper understanding I recommend this website: gitready




 The hydration lock fixes all the variables except flour and water, thus dragging flour and water changes overall weight while maintaining ratio between these 2 things.  Sounds like you would expect it to leave the starter mass and hydration in play.


My reasoning behind locking starter mass and hydration is that my starter weight/hydration is usually the one ingredient I have a fixed amount of.  I've got loads of flour and water on tap, but usually my starter is carefully weighed and prepared ahead of time.  After I lock that in and set a target hydration, I can lock the hydration and figure out what quantity I want to make without having to worry about dialing in the hydration over and over as I play with different quantities of flour and water.


If you have a specific use case in mind that the calculator doesn't support well let me know and I can see if I can accomidate you... It is early days but with good feedback it might turn out to be a decent tool.


Thanks for all your feedback!

I think what farinam and I expected was that you could lock the ratio of everything, then scale the whole recipe up. Say you normally bake two 1kg loaves. You know how much flower/water/starter you need for those two loaves. But then your friend asks you to bake them 10 700g loaves so you need to scale up to find the total dough required. This is probably beyond the scope of your calculator, considering it is a hydration calculator.



 Actually your suggestion isn't that much different from what I've already implemented, and I'm not that happy about the current lock hydration feature.  It probably makes more sense to lock all ratios and scale up.  I have created an issue on github to track this feedback and included a bit of explanation for the current behavior.  Thanks!

Hello Andrew and Joshua,

Firstly, I'll own up to pinching Joshua's idea of using sliders to set values.

I have made an Excel spreadsheet that calculates the hydration of a base recipe and also will calculate the mass required for a nominated dough mass.  At this stage I don't have the facility to fix the starter mass similar to Joshua's, but will work on that.

I guess the only question is how could this be made readily available to anybody who wanted it (if anybody did).